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I. L. SCHROEDER.

STEAM PISTON. No. 306,436. Patented 00t.14, 1884.

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ISAAC L. SOIIROEDER, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO ELLEN ADELLE HALLETT, OF SAME PLACE.

STEAM PlSTON.

EPECIFICATION forming part of Letters Patent No. 306,436, dated October 14:, 1884'.

Application filed January 3, 1884.

(No model.)

To all whom it may concern:

Be it known that I, Isaac L. SOI-IROEDER, a citizen of the United States of America, residing at Ohica go, in the county of Cook and State of Illinois, have invented certain new and use ful Improvements in Stearn-Pistons, of which the following is a specification, reference being had therein to the accompanying drawings.

llIyinvention relates to that class of pistonpackings wherein the packing-rings are maintained in contact with the interior of the cylinder by means of a series of springs which exert an adj ustable elastic pressure thereon.

The object of my invention is to obtain a simple arrangement of parts whereby the piston-ring will be operated upon with uniformity and equal pressure from all points.

The invention therein consists in the construction, arrangement, and combination of the several parts of the device, all as more fully hereinafter described, and pointed out in the claims.

For the better comprehension and understanding of my invention, attention is invited to the accompanying drawings, in whichbetween which areinterposed the usual divided metallic packing-rings D D. The heads 0 O of the piston are of ordinary construction,

except that they are each provided with an interior annular recess, a, concentric with the piston-rod. These recesses are of a diameter sufficient to permit of the longitudinal movement of a hub or core, E,which is shapedlike a cone, and is keyed or otherwise suitably mounted upon the piston-rod between the two heads of the piston. This cone-shaped hub or core is provided upon its external periphery 4 5 with. four or more dovetail grooves, 12 b b 1), ar-

ranged around the same at points equidistant apart. In each of these grooves b is inserted a wedge-shaped block, 0, the outer periphery of which is parallel with the axis of the piston, while its inner periphery inclines away d formed by the recesses a in the piston-heads,

and said shoulders secure the blocks against movement in a longitudinal direction, which is contrary to the movement of the cone-shaped hub or core E, the purpose of which will be hereinafter fully understood.

To the outer periphery of each block 0 is secured, by screws or other suitable means, a curved metallic spring, F, the two ends of which bear with equal pressure upon the interior of the packing-rings D I).

G G are two set-screws which. pass through the outer head or disk of the piston and bear against the larger head of the coneshaped hub or core E.

To force the packing-rings against the 'inte- 7O rior of the cylinder with any desired pressure, it is only necessary to apply a socketwrench to the heads of the set-screws, and in turning they press the hub forward upon the pistonrod, and this movement simultaneously eX- pands all the blocks 0, and the springs F are in turn pressed uniformly and with equal pressure against the interior of the packing-rings. The limit of the tension or pressure will of course dcpendupouthe strength and elasticity 3 shaped hub mounted upon the piston-rod and 5 provided with dovetail grooves within which fit Wedgeshaped blocks having inclined in I ner peripheries, and each provided with a! curved spring, substantially as described. I

2. In a piston-packing of the substantial character described, the c0n1bination,with the I said heads having a set screw or screws for operating said hub, substantially as described. 10

In testimony whereof I affix my signature in presence of two Witnesses.

ISAAC L. SOHROEDER. sliding cone-shaped hub, of the piston-heads each provided with an interior annular recess concentric with their axis, and one of XVitnesses:

Jam. 0. SOHROEDER, E. M. FOWLER. 

